Stephanoceras is an extinct genus of Stephanoceratoid ammonite which lived during the Bajocian. It is the type genus of the family Stephanoceratidae.
Xipheroceras is a Lower Jurassic ammonite belonging to the Eoderoceratidae, and sometimes placed in the subfamily Xipheroceratinae for which it is the namesake. It has been found in the upper Sinemurian of Europe and possibly Borneo.
Balticeras is an involute, discoidal Upper Jurassic (Oxfordian) ammonite found in England, Germany, and Switzerland, belonging to the Perisphinctidae. The shell is strongly embracing, tending to be oxyconic. Sides are gently curved, converging on a narrow to sharp ventral rim.
Kosmoceras is a moderately evolute ammonite genus from the upper Callovian of Europe with a simple apterure and irregular ribbing interrupted by an irregular row of lateral tubercles. Strong ventral tubercles are separated by a smooth depression running along the rim.
Stephanoceratoidea, formerly Stephanocerataceae, is a superfamily of middle- upper Jurassic ammonoid cephalopods within the order Ammonitida containing diverse forms, generally with sharp ribbing and complex suture lines. Aptychi are believed to be mostly granular (Granulaptycus) or concentrially ribbed on the surface (Praestriaptychus)
Oxynoticeratidae is a family of true ammonites included in the superfamily Psiloceratoidea.
Eoderoceratoidea is a superfamily of true ammonites from the Lower Jurassic, comprising seven phylogenetically related families, characterized in general by having ribbed evolute shells that commonly bear spines or tubercles. Adult shell size ranges from 2 or 3 cm to giants reaching 50 cm in such genera as Apoderoceras, Epideroceras, and Liparoceras.
Eoderoceratidae is the ancestral and most primitive family of the Eoderoceratoidea; lower Jurassic ammonite cephalopods, characterized by evolute, commonly serpenticonic, shells that had long body chambers and would have had no stable floating position; and thus resemble contemporary Psiloceratoidea. Spines, or tubercles, are typically found in two rows on the inner and outer parts of the whorl sides, joined by radial ribs. These are often more developed on the inner and middle whorls, becoming less so or absent on the outer. Sutures are highly complex.
Liparoceratidae is a family of eoderoceratoidean ammonites from the Lower Jurassic that combines genera with a variety of forms including dimorphs that change from one form to another during ontogeny.
Berriasellinae is a subfamily of very late Jurassic and very early Cretaceous perisphinctoid ammonites in the family Neocomitidae. Berriasellinae comprises generally compressed, evolute genera, typically with furcated ribbing, and in some a smooth ventral band or groove. Berriasellinae are derived from the Ataxioceratidae and gave rise to the other Neocomitidae. The short lived Himalayitidae from the uppermost Jurassic have a similar appearance but differ in being generally broader and having sharper ribbing.
Perisphinctoidea, formerly Perisphinctaceae, is a superfamily of Middle Jurassic (Bajocian) to Lower Cretaceous (Barremian) ammonites, commonly with evolute shells with strong ribbing that typically divides about mid flank before crossing the venter.
The Haploceratidae is the type family of the Haploceratoidea, a superfamily in the ammonitina; which according to Donovan et al. (1981) can be derived from the Taramelliceratinae, a subfamily of the Oppeliidae.
Oppeliidae are compressed to oxyconic, sculptured Haploceratoidea, either unkeeled, unicarinate, bicarinate, or tricarinate; with sutures in great variety, but ribbing usually more or less falcoid or falcate. The Oppeliidae is the principal family of the Haploceratoidea, with the longest duration, extending from the Middle Jurassic (Bajocian) to the Upper Cretaceous (Cenomanian) Their derivation is from the Hildoceratoidea.
Idoceras is a genus of perisphictacean ammonite, belonging to the Perisphinctidae subfamily Idoceratinae. The genus is known from the Upper Jurassic, with a widespread distribution. Shells of Idoceras are evolute, with a wide umbilicus; ribbing strong, bifurcate high on flanks. Suture simpler than in the similar Ataxioceras.
The Aspidoceratidae comprise a family of middle and upper Jurassic ammonites that make up part of the superfamily Perisphinctoidea, characterized by evolute shells, commonly stocky, that tend to develop tubercles.
The Peltoceratinae comprise a subfamily in the Aspidoceratidae,.
The Aspidoceratinae is a subfamily in the perisphictacean ammonite family, Aspidoceratidae found world wide in middle and upper Jurassic sediments.
Streblitinae is a subfamily of Upper Jurassic and Lower Cretaceous ammonites within the family Oppeliidae characterized by compressed, involute shells; typically oxycones with complex sutures. Includes Streblites, Pseudoppelia, and Substreblites. Derivation is from the Taramelliceratinae. May have given rise to the Aconiceratinade.
Hammatoceratidae is a family of lower and middle Jurassic ammonites included in the superfamily Hildoceratoidea.
Hammatoceras is a genus of ammonites belonging to the family Hammatoceratidae which lived during the Late Toarcian stage of the Early/Lower Jurassic between about 184 and 175 million year ago.
